spring - why `EntityManager` work,but EntityManagerFactory did not work for me? -

i try use spring+jpa+hibernate , try inject entitymanagerfactory,and later create entitymanger in code.but when use entitymanager.persist(user),the user not saving database.but when try inject entitymanager instead of entitymanagerfactory,it worked !,i not know problem.

you can see question more code.

when using plain entitymanagerfactory instead of entitymanager need call createentitymanager. create new entitymanager, plain entitymanager not managed nor detected spring. have start/commit transactions yourself.

when using entitymanager obtain transactional synchronized instance, managed spring , bound current transaction. no need start / commit transaction yourself.

see jpa section of reference guide.